Convert the original Terashake datasets into the volume datasets.

convertfloat:  Convert a single file.
convertfloatm: Convert multiple files at once.
convertfloatdiff: Compute the difference between two consecutive time steps.
convertseismom: Convert all values of a single position into a ASCII file that gnuplot can read.
convertvector: Convert a single file into its vector representation (i.e. vector length).
convertvector: Convert multiple file into its vector representation (i.e. vector length).